According to Harvard Medical School, metabolism – also known as metabolic rate – is a “series of chemical reactions in a living organism that create and break down energy necessary for life.” Or put simply, it’s the rate at which your body expends energy and burns calories.

If you have a fast metabolism, it means your body burns more calories during rest as well as during activity. It also means you’ll need to take in more calories to maintain your weight. As expected, someone with a low metabolism is the opposite – meaning they burn fewer calories at rest and during activity, and have to eat less if they want to avoid weight gain, the school says.

So is there anything one can do to turn around a slow metabolism?

According to experts: not really – but there some that argue that there are things that can be helpful.

In fact, the speed of your metabolism largely comes down to a few factors, one of them being genetics, Harvard Medical Schools says.

Other major factors include age and gender, registered dietitian Andrea D’Ambrosio of Dietetic Directions says.

“After age 40, metabolism will naturally slow by about five per cent per decade,” she says. “Gender also plays a role in metabolic rate; men generally burn more calories than women.”

Body composition (the more muscle we have, the higher our metabolisms), protein intake, hormones, stimulant use (like caffeine, which speeds up metabolism temporarily), fasting (which lowers metabolism) and environmental temperatures (i.e. when it’s hot or cold out, our body burns more calories trying to keep itself at a constant temperature) are also considered to have an impact on metabolism, registered dietitian Tristica Curley of Fueling with Food adds.

“Many factors are within our control,” Curley says. “For example, by being more active and eating enough protein, we can increase our metabolism.”

When it comes down to weight control, though, your metabolism isn’t the only thing that’s helping or hurting you from losing weight – it is only part of the equation. For example, the amount of food one eats and the caloric intake impacts your weight as well.

So while you may not be able to change the way your metabolism works, there are still ways you can manage your weight and balance your calories, D’Ambrosio says.

Eat breakfast: “Think of [breakfast] as ‘fuel to the fire,’ she says. “We want to start your metabolism or body burning calories first thing. If breakfast is skipped, our body tends to conserve and hold on to calories.” Those who skip breakfast, she says, are also more likely to eat higher amounts of foods, to compensate, later in the day.

Build muscle mass: Muscle burns more calories than fat, D’Ambrosio says. To be specific, a pound of muscle burns about six calories per day compared to two calories a day for a pound of fat. “If you want your body to burn more calories, you had better build extra muscle mass,” she says. “This is why a person with higher muscle mass will burn more calories and have a higher metabolism at rest than a person with less muscle mass.” Focus on doing resistance or strengthening exercises at least twice a week.

Get aerobic: This type of exercise is especially good in the hours following a workout, D’Ambrosio says. “Aerobic exercise burns more calories than resistance training,” she says. “Therefore, think of aerobic exercise as the better way to boost metabolism in the short term and strength training as the better way to boost metabolism in the long term.” Aim to do high-intensity exercise like spinning, jogging or a step class two to three times per week.

Source of protein at every meal: “Protein requires more energy – about 25 per cent more energy – to digest compared to fat and carbohydrates,” D’Ambrosio says. “This is why it is important to have one source of protein at every meal to help feel full until the next meal or snack.” However it’s important to note that our body still needs carbs as it’s the body’s main fuel source, she adds.